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The Valentine tanks: Poole's D-Day Heritage

Few have heard of the key role played by the Duplex Drive (DD) tanks in the Normandy Landings in June 1944. Yet without these amphibious vehicles it is likely that World War Two would have endured significantly longer, and very likely allowed the Soviet drive to have reached far further west. Poole in Dorset was an important training ground for the D-Day Landings, particularly for the crews of these amphibious vehicles. During these exercises seven of these tanks were lost and six men died.

MAST is a partner with Bournemouth University (BU) which is leading a project to investigate the nature, survival and state of preservation of these historic monuments. The Ministry of Defence (MoD) Salvage & Marine is another project partner alongside English Heritage. BU students have played a key role in the diving and research operations. The project is designed to contribute to the development of a methodology for understanding historic steel shipwrecks and transfer the knowledge gained into the student community and hence aid their employability.

Now, on the 75th anniversary of the DDay Landings, following six years of work in partnership with Plymouth and Bournemouth Universities, Southsea BSAC, Mark Dunkley of Historic England and the Joint Nautical Archaeology Policy Committee (JNAPC), the seven sunken tanks in Poole Bay, Dorset, have been designated under the Ancient Monuments and Archaeological Areas Act 1979.

MAST were with Bournemouth University at Tankfest for the launch of the digital dive trail in June 2019. To learn more about the project see BU's webpage.

A photo of BU students with Dave Parham, Senior Lecturer in Marine Archaeology, who is leading the project
BU students with Dave Parham, Senior Lecturer in Marine Archaeology, who is leading the project

Such sites bring management challenges. Whilst the management of modern submerged steel infrastructure is a developed subject, little is known about similar historic structures. Research into this subject has been limited and is still being developed, some of which is being undertaken by BU.

The heritage community is not alone in this management. The UK government is responsible for the management of wrecks, such as these vehicles, that are also potential ocean pollutants (‘legacy wrecks’). The MoD is currently conducting research to better understand the physical state and corrosion of these wrecks and hence risk assess their ability to contain these pollutants.

Photogrammetry survey results of the seven tanks by Bournemouth University in partnership with MAST.

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The history

The Duplex Drive tanks were normal tanks made buoyant by the provision of a canvas skirt.

They were propelled by a Duplex Drive which connected two propellers to the tank’s engine. They formed a key component of the plan for the Normandy landings and later WW2 landings in southern France on 15th August 1944, a seven mile crossing of the Western Scheldt on 26th October 1944 during the Battle of the Scheldt, the Rhine crossing on 23rd March 1945 and in Italy the crossing of the Po River on 24th April 1945 and the River Adige on 28th April 1945.

A photo of A Sherman DD tank in Poole Bay c.1944
A Sherman DD tank in Poole Bay c.1944
A photo of A DD Sherman tank. The screens took 15 minutes to inflate. Photo courtesy of IWM Film
A DD Sherman tank. The screens took 15 minutes to inflate. Photo courtesy of IWM Film

To defeat Nazi Germany the western allies had to land an army on the coast of France and fight through France into Germany, meeting the Soviet Army invading from the East. The Germans meant to defeat them on the beaches, preventing the allies from advancing. The Atlantic coast of France had become a fortress (the Atlantic Wall) with strategic locations bolstered even further.

The role of the DD Tanks was to provide armoured support for the first waves of infantry ashore. To achieve this they were to ‘swim’ ashore about five minutes ahead of the first wave of infantry, provide support to the initial landings and then support the infantry in capturing German strong points to allow the beachhead to be secured and to assist the subsequent build up of resources needed to ensure the invasions success.

The concept was largely successful with the exception of Omaha beach where the DD tanks were swamped and sank offshore in 1.8m waves. They were designed to operate in seas with over 30 cm of ripple. The lack of armoured support on the beachhead was a major contributing factor in the heavy casualties suffered by the US Army at Omaha and the problems encountered in securing this beachhead, which was eventually secured with the aid of the few tanks that did land.


General Sir Robert Ford, was a survivor of these losses (then a Lieutenant in the 4th/7th Royal Dragoon Guards). On the 60th anniversary of the losses he told the Bournemouth Daily Echo on 5th April 2004

We were on the surface of the water after coming off the landing craft and becoming increasingly apprehensive. The water was coming in very fast and although we had small pumps, they were just not effective. The weight of the water against the canvas was just too great. We knew we weren't going to make it. We were still floating and all four of us were standing on the top of the tank. Then a great wave crashed over the top and we sank to the bottom. The canvas enveloped and I knew we were trapped. I lost the mouthpiece from my lifesaving equipment and so it was useless. I was able to take a couple of short gasps of oxygen because we seemed to be in a bit of an air pocket. Then I realised I was only trapped by my feet so with my lifejacket I managed to rise to the surface. It seemed a long way back up. Unfortunately my colleagues did not make it.

Six men died in Operation Smash and seven tanks were lost in Poole Bay in April 1944, while training for D-Day. (Initially DD Valentine Tanks were used for training and later DD M4 Sherman tanks used during the Landings.) The most acclaimed film of the D-Day landings is the scene from the 1998 film Saving Private Ryan which accurately depicts the chaos of the landings at Omaha beach, caused in no small part by the failure of the DD tanks to reach the beach. If these scenes had been repeated across the entire front on D-Day the chances that the invasion would have failed must been considered.

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